Meter ink



Patented Aug. 1944 Westinghouse Electric & Manufacturing Company, EastPittsburgh, Pa., a corporation of Pennsylvania No Drawing. ApplicationMay 22, 1942, Serial No. 444,112 v 4 Claims.

This invention relates to an ink, more particularly'an ink suitable foruse in recording meters and in blue-printing.

This application is a continuation-in-part of application Serial No.341,137, entitled Meter ink, filed June 18, 1940. I

The object of this invention is to provide for a red ink, particularlyfor use in recorders.

Other objects of the invention will appear from the followingdescription and claims.

The service'requirements for inks, such as are employed in recorders andother instruments, call'for a fast drying and stable marking fluid whichwill withstand considerable exposure in recorder pen fountains to theatmosphere without clogging or thickening. The service is so exacting,that, in general, fillers of any kind may not be employed in the ink. Asupply of ink sufficient to last for one or more days is placed in thepen of the recording instrument and the ink is expected to performwithout failure irrespective of the humidity, temperature and othercharacteristics of the locality within which the recorder is located.The trace made bythe pen should be of uniform width, of uniform colorand with no uninked portions of a pen trace no matter how rapidly thepen moves or how long the pen stays in a given spot.

According to the invention, a composition for a red ink has beendiscovered'which meets the service requirements to a high degree. Theink comprises a major amount of a red dye and a yellow dye and solventtherefor, the dyes being periectly soluble in the solvent in anextensive range of proportions. I

The red dye which is the fundamental color base of the ink is the sodiumsalt of benzene-azubenzene-azo-B-naphthol 6:8-disulphonic acid,corresponding to the following chemical struc- NBOaS I V sNa type isemployed. The yellow tartrazine dyes correspond to the following generalformula:

N8S0:CqH4*-. N

' N=CCOONa The specific yellow tartrazine employed is the highlyconcentrated dye having a Color Index number of 640. If the less highlyconcentrated .tartrazine dye normally available to the trade isemployed, then it may be necessary to use a greater quantity thereofthan indicated hereinafter.

uitable solvents for the two dyes are a composition of about 13 7?)glycerine preferably of a chemically pure grade concentrated, about 68%of distilled water, about 18% of ethyl alcohol and about of a preferablychemically pure acetic acid, 28% concentrated. The acetic acid acts as apreservative and increases the solubility of the dyes in the solvents.

, The ethyl alcohol in the above formula may be a denatured alcoholcontaining 5% methyl alcohol.

The solvent liquids are mixed in a suitable container and are warmed toapproximately 38 C. and stirred until thoroughly combined and thereafterthe dyes may be added. A satisfactory ink composition consists of onegram of the yellow tartrazine dye and 1% grams of the red dye dissolvedin about milliliters of solvent. The solution is stirred at 38 C. untilthe dyes have completely dissolved. The solution is allowed to cool toroom-temperature (20 C.) and is thereafter filtered. The ink is readyfor use after filtering.

A convenient method of measuring out therequired volume of the liquidsused for the solvent is to combine l5 milliliters of 95% glycerine. 75milliliters of distilled water, 20 milliliters of ethyl alcohol'andmilliliter of 28% acetic acid. One gram of yellow tartrazine dye and 1%grams of red dye dissolved in this quantity of solvent by the abovemethod will result in the desired ink.

Another formulation for a dye composed of the time same ingredients ashereinbefore disclosed,'but requiring more time for drying, consists of:

This formulation may be used for all the purposes that the first inkcomposition may be employed, but does not exhibit as intenseblueprinting qualities due to thelesser proportion oi.

yellow dye.

It is preferred for recorder applications to keep the amount of yellowdye less than the amount of red dye employed. The J quantity,

however, may be varied to suit requirements,

Increasing the amount of red with respect to the yellow results in adeepershade of red being obtained, but this sacrifices some of theblueprinting quality. .If'the amount of yellowtartrazine dye is muchgreater'than that of the red, the red will appear somewhat pale. Anincrease of yellow dye enhancesthe intensity for blueprinting purposes'For the .purpose of this invention, the dyes may be admixed-inproportions ranging from 1 to 8 parts by weight of'the red dye to eachpart by weight of the yellow tartrazine' dye. The formulationscontaining the higher proportion Red dye grams :2

Yellow tartrazine dye do Glycerine c.c 40 Water do 75 Alcohol do Aceticacid do" A pable of being volatilized without leaving any gumor'residu'e.

The polyhydric alcohols present in the ink are hydroscopic materialstending .to absorb moisture from the atmosphere, thereby preventing theink vinthe'pen from drying out.

However, upon tracing aline onpaper, the'polyhydric alcohols will bereadily absorbed by' the 'papeiq-leaving a dry trace consisting of thedyes.

The'amount'of solvent used for a given'quantity of dye-may be'varied.However, if a greater quantity of solvent is used "than the amountindicated abovefora given weight ofthe dye, 'then theinkwilltraceathin-and pale appearing line and will not have much body. If theindicated amount of solvent is greatly decreased tfor a given weight'ofdye, less ink 'for a given quantity of dye ismade and no compensatingvadvantage in color or effectiveness is'obtained. In addition, if theproportion of alcohol in the first example isreduced one-half, the inkdries "slowly and isnot as satisfactory for recorder jpurposes. l

Thecoinposition and amounts given above are those best suited'for thepurposes set forth but "departure from such specific quantities can beof yellow dye to red dye will give the moreintense lines uponblueprint-mg, but all of the proportions within this range will besatisfactory in blueprinting charts prepared therefrom.

In producing inks by dissolving the dyes in solvents, it is desirable toemploy solvents prepared by combining a monohydric alcohol, a polyhydricalcohol, water, and apreservative if it be desired. Suitable monohydricalcohols are ethyl alcohol,

denatured alcohol, methyl alcohol, and butyl alcohol. Examples ofpolyhydric' alcohols, in addition to glycerine as disclosedhereinbefore,

are ethylene glycol, propylene glycol, and "di-' ethylene glycol. Phenolis a satisfactory substitute for acetic acid to function as apreservative. The following formulae are examples of suitable, solventand dye combinationsz' In some cases, other organic solvents that aremiscible with water, alcohol and polyhydric,

alcohol may be employed in producinga satisfactory recording ink. :Themain requirement,

for the solvents is that they do notform gums when exposed to theatmosphere for periods of Furthermore, the solvents should be ca- 'madewithin reasonable ,limits without great variationin theproductand suchvariations are within thescope of the present invention.

I claim as my. invention: 1.An ink comprising 1 gram of yellowtartrazine dye of Color'IndexNo.640, one and onequarter grams of sodiumbenzene-azo-benzeneazo-B-naphthol-Gz-8-disulphonlc acid, 15 milliliters.of 'glycerine, milliliters distilled water,

20 milliliters ethyl alcohol and milliliter of 28% acetic acid, thewhole'being compounded to effect a fast drying and stable red ink.

2. 'A-red ink suitable for recorders and for blueprinting composed of 1gram of yellow tartrazinejdye :1 grams; of sodium benzene-azobenzene azoB'- naphthol-6:8-disulphonic acid to providefor the red coloring andsolvents for the dyes consistingessentially of 'glycerine. ethyl alcoholand water, the solvents being capable of clryingandleaving-substantially no residue, the whole being compounded to eifect astable, non-.

clogging and fastfdrying ink.

3. A red ink for usein recorders comprising a color base composed of 1%to 2 grams of sodium benzene razo benzene-azo-B-naphthol-6:8-disu1phonic5acid and 1 to gram of yellow tartrazine dye having aColor Index number of 640, the color-base being dissolved in over 110milliliters of a volatile solvent composed -of 'glycerine,ethyl-alcohol, water and acetic acid,

the whole effecting-a fast drying, non-clogging and stable ink.

[4. A redink suitable for use in recorders for 'preparing'charts thatmay be'blueprinted effectively,,comprising a-color base composed of onepart by weight of a yellow tartraz ine dye of .Color Index "No. 640andabout from one to eight parts of sodium benzene-azmB-naphthol-fi:8-dlsulphonicacid, one part of-the color base being dissolved-in 20:toparts of a non-gumming,

substantially completely. volatile solvent composed of amonohydricalcohol having from i to 4 carbon atoms, a liquid polyhydric alcohol, apreservativeand water.,

, THOMAS J. KEATING.

